Comparative Effectiveness of the Mckenzie Method and Williams Flexion Exercises in Muscular Imbalance and Pain in Lower Cross Syndrome

Abstract

Background: Lower Cross Syndrome (LCS) is a muscular imbalance marked by tight hip flexors and lumbar extensors and simultaneous weakness of abdominal and gluteal muscles and it is usually accompanied by chronic low back pain (LBP). McKenzie Method and Williams Flexion Exercises have been extensively deployed in mechanical LBP but the comparative effectiveness of both techniques in clinical defined LCS has not been investigated before.  Methods: 56 participants over the age of 18 and 45 years of age with clinically diagnosed LCS and chronic non-specific LBP were randomized (1:1) into McKenzie (n=28) or Williams (n=28) groups. The two groups were given supervised exercises in three sessions per week and lasted eight weeks. The pain (VAS) and functional disability (ODI) were the primary outcomes. Secondary outcomes were hip flexor (Modified Thomas Test) and core endurance (plank and bridge tests). The results were measured at the pre-intervention and post-intervention. Results: Both of the groups showed high within-group changes in the results (p<0.05). however, Williams group demonstrated much better post intervention results than McKenzie group such as better VAS scores, more ODI improvement, more increase in hip flexor ROM and better plank and bridge endurance (p<0.05). Conclusion: The Williams Flexion Exercises showed more effective than the modified McKenzie protocol in pain reduction, disability, flexion, and core endurance of LCS patients. Muscle-balancing interventions are flexion-based and seem more biomechanically suitable in LCS and could be regarded as the most appropriate exercise strategy during the clinical management.